The present invention relates to a valve arrangement for a pressurized water purifier of the kind which comprises an inlet conduit, a pressure-elevating pump incorporated in the inlet conduit, a filter or membrane type purifying unit, a purified-water outlet conduit, and a reject conduit for concentrated non-purified or contaminated water.
A problem with known pressurized water purifiers resides in the difficulty of achieving a uniform or non-pulsating output flow of purified water independently of the size of the flow. This problem is associated with the fact that in order to overcome the filter or membrane counterpressure, it is necessary for water purifiers of this type to operate at an internal pressure greater than 1 MPa, this pressure of 1 MPa being the maximum pressure for which a domestic water system in which the water purifier is installed is normally constructed.